Most of the ordinary domestic refrigerators belong to vapour compression-type refrigerating systems, which realize a control on the temperature in the refrigerators by controlling the on and off of a compressor. However, when the compressor stops working, the pressures in the condenser and the evaporator tend to be balanced, and during the balancing process, the hot-state refrigerant flows into the evaporator via capillary tubes, which causes a part of meaningless energy dissipation to the refrigerator. When the compressor is started, a part of energy will be lost during the process that the condenser and the evaporator reestablish a pressure difference, and the more frequently the refrigerator is turned on and turned off, the more energy will be dissipated. This part of energy dissipation caused by the on and off of the compressor will cause the power consumption of the refrigerator to rise.
Chinese patent application No. 03112681.2, titled “condenser pressure maintaining and energy saving-type refrigerating system for refrigerator” disclose a condenser pressure maintaining and energy saving technology, which closes the outlet of the condenser instantaneously by an electric valve at the time the compressor stops, so that the pressure difference between the condenser and the evaporator is maintained, and the hot-state refrigerant is prevented from flowing into the evaporator to influence the refrigeration effect. When the compressor is started again, the process of reestablishing a pressure difference may be omitted, and the refrigeration of the refrigerator may be realized rapidly. In order to help the compressor to start and lower the pressure in the exhaust pipe, a “pressure relief” loop including a one-way valve further needs to be designed at the inlet position of the condenser for the above “condenser pressure maintaining and energy saving-type refrigerating system for refrigerator”. For such a traditional condenser pressure maintaining and energy saving technology, the electric valve used belongs to a “two-position and two-way” bistable pulse solenoid valve, of which the movement switching mode of the valve core is straight line back and forth impulse mode. Such a solenoid valve has a biggest defect of large action noise, and it cannot realize the “pressure relief” function by itself, so that a dedicated “pressure relief capillary tube” with a condensation function needs to be designed specially or a “two-position and two-way” pressure relief solenoid valve needs to be added, thereby problems of “slow response” of the pressure relief loop, poor close performance of the one-way valve, a large number of parts and components and unstable energy saving effect of the refrigerator will be caused.